Most hinges used on sectional garage doors are three-piece hinge assemblies that consist of two leaves and a pivot pin. These components of the hinge assembly can be made of metallic or non-metallic materials. The pivot hinge can be a tubular or solid shaft that is threaded through the two leaves and staked, flared, or bradded into place. The leaves are designed to interlace each other such that there is little or no movement along the axis of the pivot pin. Alignment on these hinges is critical in that they must be aligned both horizontally and vertically to ensure proper movement of the hinge through its operating range without binding.
To provide for rotation between components, a variety of hinge constructions have been employed in the prior art. One construction utilizes a “living hinge” which includes a portion of plastic material connecting the various components. Living hinges tend to experience fatigue failure when used repeatedly or when used over a wide pivot range.
Another hinge construction includes pins and sockets formed directly within the parts to be joined. In one form a blow-molded container having has an integrally formed pin and socket forming a journal. The socket is formed from a flexible wall portion that extends beyond the main body of a lid. The socket, which is generally centered between the pins, flexes over the pins when the lid and base are brought together. While this construction enables the fabrication of an assembly having an integrally blow-molded hinge, the assembly has several disadvantages. The socket is made to have a spacing that lies at the midpoint of the pins when the base and lid are assembled. This allows the lid to slide transversely along the pins. Since the hinge is not self centering, this transverse movement may result in a misalignment that impairs the ability to open or close the members. The movement may also permit unwanted “play” between the members.
In another design having integrally formed blow molded hinge components, the components are made without additional fasteners, pins or sockets. The parts are made from a rigid plastic material that need not flex to be assembled. This enables the repeatability needed for high speed manufacturing operations and also reduces the possibility of inadvertently damaging the hinge by over flexing one of the components.
Turning to the upwardly acting door art, hinges are widely used in “sectional door” designs. These door designs incorporate a number of pivotally joined sections that may be successively raised or lowered within a door opening.
Sectional doors, such as multi-panel garage doors, have presented a pinching hazard at the juncture between adjacent panels as the door closes and the panels shift to an aligned vertical position. Prior art attempts to solve this problem have met with only limited success, sometimes presenting mechanical complexity or uneconomical designs. For example, one attempt at addressing the aforementioned problem includes a plurality of adjacent door panels, a hinge pin received in respective registered hinge pin holes defined in a bracket and brace. The adjacent panels present mated, arcuate edge walls. The bracket and brace are configured to position the hinge pin adjacent the one panel and spaced from the juncture so that the gap between the edge walls closes gradually and so that the edge walls slide by one another during movement from the pivoted position to the aligned position.
Another pinch-proof garage door design for protecting human fingers from being pinched includes a plurality of horizontally aligned garage door panels having a top male portion and a bottom female portion. Top male and bottom female portions of adjacent garage door panels cooperate with each other in such a manner so as to minimize a gap therebetween, thereby protecting human fingers from being pinched by both the inside and the outside of the garage door. Each garage door panel is securely fastened to a structural member, which supports the weight of the panel. Adjacent structural members are vertically aligned with one another and are coupled together by a hinge pin and hinge leaf. Each structural member cooperates with an adjacent hinge leaf so as to prevent human fingers from being pinched by the inside of the garage door.
Still another design features a hinge assembly that affords very simple and efficient installation of the hinge during the assembly and installation of the door while still minimizing and, in fact, reducing the number of component parts relative to other known hinge designs. This design includes a generally U-shaped beam or stile that extends between the upper and lower edges of the back face of each panel. Proximate an upper end of the stile, is a keyhole slot extending through or into the stile. A first lower portion of the hinge also includes a similarly configured keyhole slot. A pivot pin, which includes a protruding key, is inserted through the keyhole slots in the hinge and the stile when the keyhole slots are aligned. Alignment of the keyhole slots requires positioning an upper portion of the hinge away from the stile on the adjacent panel to which the hinge will eventually be connected. After the pivot pin is inserted through the keyhole slots, the hinge is pivoted so that the upper portion is then bolted or otherwise connected to the stile on the adjacent panel thereby completing the assembly of the hinge to the adjacent panels. Because the keyhole slots are out of phase when the hinge is finally connected to the panels, the pin cannot be removed. As a result, the assembly method of the hinge according to this invention does not require a separate fastener for the pivot pin thereby simplifying the installation procedure and minimizing inventory and tracking requirements for the component parts of this invention. Advantageously, the pivot pin and the resulting pivot axis of the hinge is positioned on the stile inwardly from the back face of the panels and between the front and back faces thereof to enhance the pinch-resistant aspect of this design while minimizing material requirements. Specifically, the pivot axis is approximately coincident with the center of curvature of the lower edge of the adjacent panel. The cross-sectional configuration of the concave lower edge of the adjacent panel is non-circular with several polygonal sections or linear segments. The focus of perpendiculars to the polygonal sections at the respective midpoints of the faces of the polygon is at a spot at or near the pivot axis. Preferably, the center of curvature of the polygonal areas defining the concaved lower edge is generally concentric with the pivot axis of the hinge and substantially spaced from the back face of the panel toward the front face of the panels. This hinge design aids in the making the door pinch resistant.
As can be seen from the above described designs, the prior art discloses many different hinge designs that attach adjacent sections or panels together and provide a pivot point for the sections. Most of these prior art hinges are modular assemblies that have little or no movement along the axis of the pivot so care must be taken during installation of the hinge to precisely align the hinges between the adjacent sections so that all of the pivots are on the same axis or binding will occur.